Gothenburg and Stockholm are among the most important of some 20 ports handling foreign trade. The forest industry adjacent to the Norrland coast has its own harbours, which in winter are dependent on icebreaker services.
The Swedish merchant fleet has been drastically reduced by competition from foreign ships charging lower rates. Ferry traffic between Sweden and its neighbours has grown tremendously and increasingly employs larger and more luxurious ferryboats.
In the first half of the 19th century a number of inland waterways, among them the Göta canal, were constructed. They soon became obsolete, however, as the state began in the 1850s to build the national railway network. Sweden soon ranked among the foremost countries in per capita mileage of railroads.
Railroads in their turn met competition from the automobile, and since the 1950s many secondary rail lines have been closed. The centuries-old road network was rapidly expanded in the 20th century, and ever-better roads were built. Highways ran between Stockholm, Gothenburg, and Malmö and connected the capital to the northern coastal region. Most households own at least one car. Local public bus transportation is well developed, but only Stockholm has a subway as the backbone of its local transportation system. Gothenburg has developed a tram system.
Air services are dominated by the Scandinavian Airlines System (SAS), which is owned chiefly by the states of Sweden, Denmark, and Norway. The interests of SAS are concentrated on international aviation, but, directly and indirectly, it also dominates domestic service. The most important airports are in Stockholm, Gothenburg, and Malmö.
The interests of the state in transportation and communications are wide. The railways are owned and run by the state, which also maintains bus traffic on a large scale.
